Abstract: Objective To develop an alignment technique based on the movement of body gravity center. Methods As join forces in the system of balance is zero, the position of body gravity center can be calculated by body gravity which is taken from weight sensors, by the special software. Meanwhile, the position of body gravity will be sent to control unit, which can be transformed to driving signal of motor. The sliding table with laser, linked to motor, can make pursuit movement following with body gravity. A precise alignment can be made as the movement of body gravity. The balance function test is also used to make an assistant estimate for the alignment. Results and Conclusion An alignment technique has been developed for the fit of prosthesis and orthotics.

Key words: gravity center, alignment, suitability, prosthesis, orthotics, balance